CONSOLIDATED BALANCE SHEETS (PARENTHETICAL) - $ / shares shares in Thousands	Dec. 31, 2016	Dec. 31, 2015
CONSOLIDATED BALANCE SHEETS
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	150,000	150,000
Common stock, shares issued	33,971	32,209
Common stock, shares outstanding	33,943	32,181
Treasury stock, shares	28	28